Dye developer color liffusion transfer processes and elements comprising alpha and gamma hydroxy and gamma amino substituted pyridines

ABSTRACT

DYE-DEVELOPER DIFFUSION TRANSFER COLOR PROCESSES AND ELEMENTS AND COMPOSITIONS FOR EMPLOYMENT THEREIN, COMPRISING A COMPOUND SELECTED FROM ALPHA AND GAMMA HYDROXY AND GAMMA AMINO SUBSTITUTED PYDRIDINES ADAPTED TO REACT WITH THE OXIDATION PRODUCTS OF THE DYE DEVELOPERS TO PROVIDE DURING PROCESSING A PRODUCT WHICH IS LESS DIFFUSIBLE IN THE PROCESSING COMPOSITION THAN THE SAID DYE DEVELOPER OXIDATION PRODUCTS.

DEVELOPER 00 May 11,1 DYE M. DIFFUS SIMON 3,578,447

TRANSFER PROCESSES AND ELEMENTS COMPRISING L HA AND GAMMA HYDROXY ANDGAMMA AMINO SUBSTITUTED PYRIDINES Filed May 2 1969 )0 IZ /SUPPORT I3A\ rCYAN DYE DEvELoPER LAYER RED SITIVE SILVER HALIDE N LAYER l5* INTERLAYERH Is- -l -MAGENTA DYE DEVELOPER LAYER GREEN SENSI sILvER HALIDE EMuLsIoNLA Isl flNTERLAYER IQA\\\\\\\ YELLow DYE DEVELOPER LAYER 2o\, A BLUESENSITIVE sILvER HALIDE EMuLsIoN LAYER 3I'-: ovERcoAT LAYER 27 -:I':-'E- uEous ALKALINE PROCESSING I it: E MPOSITION 25%///I/IMAGERECEIVING LAYER 24- -SPACER LAYER 22 25- ///I -NEUTRALIZINGLAYER 2em sup om VENTO 8. SIM

ATTORNEYS United States Patent ()flice DYE DEVELOPER COLOR DIFFUSIONTRANSFER PROCESSES AND ELEMENTS COMPRISING ALPHA AND GAMMA HYDROXY ANDGAMMA AMINO SUBSTITUTED PYRIDINES Myron S. Simon, West Newton, Mass,assignor to Polaroid Corporation, Cambridge, Mass. Filed May 2, 1969,Ser. No. 821,191 Int. Cl. G03c 5/54, 7/00 U.S. Cl. %3 19 Claims ABSTRACTOF THE DISCLOSURE Dye-developer diffusion transfer color processes andelements and compositions for employment therein, comprising a compoundselected from alpha and gamma hydroxy and gamma amino substitutedpyridines adapted to react with the oxidation products of the dyedevelopers to provide during processing a product which is lessdiffusible in the processing composition than the said dye developeroxidation products.

The present invention relates to photography and, more particularly, toprocesses for forming photographic diffusion transfer color images andproducts and compositions particularly adapted for employment in suchprocesses.

Accordingly, it is a primary object of the present invention to providenovel photographic diffusion transfer color processes and novel productsand compositions particularly adapted for employment in such processes;to provide novel photographic diffusion transfer color processesparticularly adapted for the production of monochromatic andmultichromatic images; to provide novel photographic products whichcomprise a photosensitive element which includes at least onephotosensitive emulsion having associated therewith, as a colorimage-forming component, a dye of predetermined color which is a silverhalide developing agent and a nucleophilic reagent adapted to react withthe oxidation product of the dye to provide a dye adduct less diifusibleduring photographic processing than said oxidation product of said dye;to provide novel photographic products which include a photosensitiveelement which comprises at least one photosensitive silver halideemulsion having associated therewith a dye developer of predeterminedcolor and a compound selected from a group consisting of alpha and gammahydroxy and gamma amino substituted pyridines adapted to react with theoxidation product of the dye developer to provide a dye less diifusibleduring processing than the oxidation product of the dye; to providenovel photo graphic products, of the last-identified type, incombination with a photographic diffusion transfer image-receivingelement including a layer dyeable by said dye; to provide novelphotographic products comprising a film unit, of the last-identifiedtype, in combination with a rupturable container adapted to retain fluidprocessing composition affixed one edge of one of said photosensitiveand said image-receiving elements and adapted to distribute its fluidcontents in contact with said photosensitive element: to provide novelphotographic products, of the last identified type, wherein saidrupturable container retains an aqueous alkaline processing solution inwhich said dye is diffusible; and to provide novel photographicproducts, of the last-identified type, wherein said rupturable containeris positioned and extends transverse a leading edge of said film unitwhereby to effect unidirectional discharge of said containers contentsintermediate said photosensitive and said image-receiving element.

Other objects of the present invention will in part be obvious and willin part appear hereinafter.

The invention accordingly comprises the processes involving the severalsteps and the relation and order of one or more of such steps withrespect to each of the others, and the product possessing the features,properties and the relation of elements which are exemplified in thefollowing detailed disclosure, and the scope of the application of whichwill be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawing wherein:

The drawing is a diagrammatic enlarged cross-sectional vieW illustratingthe association of elements during one stage of the performance of adiffusion transfer process for the production of a multicolor transferimage according to the present invention, the thickness of the variousmaterials being exaggerated.

As disclosed in U.S. Pat. No. 2,983,606, a photosensitive elementcontaining a dye developer and a silver halide emulsion is exposed andwetted by a liquid processing composition, for example, by immersion,coating, spraying, flowing, etc., in the dark, and the exposedphotosensitive element is superposed prior to, during, or after Wetting,on a sheetlike support element which may be utilized as animage-receiving element. In a preferred embodiment, the liquidprocessing composition is applied to the photosensitive element in asubstantially uniform layer as the photosensitive element is broughtinto superposed relationship with the image-receiving layer. The liquidprocessing composition permeates the emulsion to initiate development ofthe latent image contained therein. The dye developer is immobilized orprecipitated in exposed areas as a consequence of the development of thelatent image. This immobilization is apparently, at least in part, dueto a change in the solubility characteristics of the dye developer uponoxidation and especially as regards its solubility in alkalinesolutions. It may also be due in part to a tanning effect on theemulsion by oxidized developing agent, and in part to a localizedexhaustion of alkali as a result of development. In unexposed andpartially exposed areas of the emulsion, the dye developer is unreactedand diifusible and thus provides an imagewise distribution of unoxidizeddye developer dissolved in the liquid processing composition, as afunction of the pointto-point degree of exposure of the silver halideemulsion. At least part of this imagewise distribution of unoxidized dyedeveloper is transferred, by imbibition, to a superposed image-receivinglayer or element, said transfer substantially excluding oxidized dyedeveloper. The imagereceiving element receives a depthwise diffusion,from the developed emulsion, of unoxidized dye developer withoutappreciably disturbing the imagewise distribution thereof to provide thereversed or positive color image of the developed image. The desiredpositive image is revealed by stripping the image-receiving layer fromthe photosensitive element at the end of a suitable imbibition period.

The dye developers, as noted above, are compounds which contain, in thesame molecule, both the chromophoric system of a dye and also a silverhalide developing function. By a silver halide developing function ismeant a grouping adapted to develop exposed silver halide. A preferredsilver halide development function is a hydroquinonyl group. Othersuitable developing functions include ortho-dihydroxyphenyl and orthoand para-amino substituted hydroxyphenyl groups. In general, thedevelopment function includes a benzenoid developing function, that is,an aromatic developing group which forms quinonoid or quinone substanceswhen oxidized.

Multicolor images may be obtained using color image forming componentssuch as, for example, the previously mentioned dye developers, indiffusion transfer processes Patented May 11, 1971 by severaltechniques. One such technique contemplates the use of a photosensitivesilver halide stratum comprising at least two sets of selectivelysensitized minute photosensitive elements arranged in the form of aphotosensitive screen. Transfer processes of this type are disclosed inthe previously noted US. Pat. No. 2,983,606. In such an embodiment, eachof the minute photosensitive elements has associated therewith anappropriate dye developer in or behind the silver halide emulsionportion. In general, a suitable photosensitive screen, prepared inaccordance with the disclosures of said patents, comprises minutered-sensitized emulsion elements, minute greensensitized emulsionelements and minute blue-sensitive emulsion elements arranged inside-by-side relationship in a screen pattern and having associatedtherewith, respectively, a cyan dye developer, a magenta dye developerand a yellow dye developer.

Another process for Obtaining multicolor transfer images utilizing dyedevelopers employs an integral multilayer photosensitive element, suchas is disclosed in the aforementioned copending US. Patent No.3,345,163, issued Oct. 3, 1967, wherein at least two selectivelysensitized photosensitive strata are superposed on a single sup.- portand are processed, simultaneously and without separation, with a single,common image-receiving layer. A suitable arrangement of this typecomprises a support carrying a red-sensitive silver halide emulsionstratum, a green-sensitive silver halide emulsion stratum and abluesensitive silver halide emulsion stratum, said emulsions havingassociated therewith, respectively, for example, a cyan die developer, amagenta dye developer and a yellow dye developer. The dye developer maybe utilized in the silver halide emulsion layer, for example, in theform of particles, or it may be employed as a layer behind theappropriate silver halide emulsion strata. Each set of silver halideemulsion and associated dye developer strata may be separated from othersets by suitable interlayers, for example, by a layer of gelatin orpolyvinyl alcohol. In certain instances, it may be desirable toincorporate a yellow filter in front of the green-sensitive emulsion andsuch yellow filter may be incorporated in an interlayer. However, wheredesirable, a yellow dye developer of the appropriate spectralcharacteristics and present in a state capable of functioning as ayellow filter may be employed. In such instances, a separate yellowfilter may be omitted.

An extensive compilation of specific dye developers particularly adaptedfor employment in photographic diffusion transfer processes is set forthin aforementioned US. Pat. No. 2,983,606, and in the various copendingUS. applications referred to in that patent, especially in the table ofUS. applications incorporated by reference into the patent as detailedin column 27. As examples of additional US. patents detailing specificdye developers for photographic transfer process use, mention may alsobe made of US. Pat. Nos. 2,983,605; 2,992,106; 3,047,386; 3,076,808;3,076,820; 3,077,402; 3,126,280; 3,131,061; 3,134,762; 3,134,765;3,135,604; 3,135,605; 3,135,606; 3,135,734; 3,141,772; 3,142,565; andthe like.

As additional examples of synthetic, film-forming, permeable polymersparticularly adapted to retain dispersed dye developer, mention may bemade of nitrocarboxymethyl cellulose, as disclosed in US. Pat. No.2,992,104;

, an acrylamidobenzene sulfo ester of a partial sulfobenzal of polyvinylalcohol, as disclosed in U.S. Pat. No. 3,043,- 692; polymers ofN-alkyl-afi-unsatumted carboxamides and copolymers of N-allyl-a,,8-carboxamides with N- hydroxyalkyl-nap-unsaturated carboxamides,as disclosed in US. Pat. No. 3,069,263; copolymers of vinyl-phthalimideand a,;8-unsaturated carboxylic acids, as disclosed in US. Pat. No.3,061,428; copolymers of N-vinylpyrolidones, oc,[3-unsaturatedcarboxylic acids and terpolymers of N-vinylpyrrolidones, n p-unsaturated,carboxylic acids and alkyl esters of cap-unsaturated carboxylic acids,as disclosed in US. Pat, No. 3,044,873; co-

4 polymers of N,N dialkyl-u,p-unsaturated carboxamides withcap-unsaturated carboxylic acids, the corresponding amides of suchacids, and copolymers of N-aryland N-cycloalkyl-a,,B-unsaturatedcarboxamides with u,[S'-unsaturated carboxylic acids, as disclosed inUS. Pat. No. 3,069,264; and the like.

In addition to conventional techniques for the direct dispersion of aparticulate solid material in a polymeric, or colloidal, matrix such asball-milling and the like tech niques, the preparation of the dyedeveloper dispersion may also be obtained by dissolving the dye in anappropriate solvent, or mixture of solvents, and the resultant solutiondistributed in the polymeric binder, with optional subsequent removal ofthe solvent, or solvents, employed, as, for example, by vaporizationwhere the selected solvent, or solvents, possesses a sufficiently lowboiling point or Washing where the selected solvent, or solvents,possesses a sufficiently high differential solubility in the washmedium, for example, water, when measured against the solubility of theremaining composition components, and/ or obtained by dissolving boththe polymeric binder and dye in a common solvent.

For further detailed treatment of solvent distribution systems of thetypes referred to above, and for an extensive compilation of theconventional solvents traditionally employed in the art to effectdistribution of photographic color-providing materials in polymericbinders, specifically for the formation of component layers ofphotographic film units, reference may be made to US. Pats. Nos.2,269,158; 2,322,027; 2,304,939; 2,304,940; 2,801,- 171; and the like.

US. Pat. No. 3,362,819, issued Jan. 9, 1968, discloses image-receivingelements, particularly adapted for employment in the preceding diffusiontransfer processes, which comprise a support layer possessing on onesurface thereof, in sequence, a polymeric acid layer, an inert timing orspacer layer, and an image-receiving layer adapted to provide a visibleimage upon transfer to said layer of diffusible dye image-formingsubstance.

As set forth in the last-mentioned patent, the polymeric acid layercomprises polymers which contain acid groups, such as carboxylic acidand sulfonic acid groups, which are capable of forming salts with alkalimetals, such as sodium, potassium etc., or with organic bases,particularly quaternary ammonium bases, such as tetramethyl ammoniumhydroxide, or potentially acid-yielding groups, such as anhydrides orlactones, or other groups which are capable of reacting with bases tocapture and retain them. The acid-reacting group is, of course,nondiifusible from the acid polymer layer.

In order to prevent premature pH reduction during transfer processing,as evidenced, for example, by an undesired reduction in image density,the acid groups are disclosed to be so distributed in the acid polymerlayer that the rate of their availability to the alkali is controllable,e.g., as a function of the rate of swelling of the polymer layer whichrate in turn has a direct relationship to the diffusion rate of thealkali ions. The desired distribution of the acid groups in the acidpolymer layer may be effected by mixing the acid polymer with a polymerfree of acid groups, or lower in concentration of acid groups, andcompatible therewith, or by using only the acid polymer but selectingone having a relatively lower proportion of acid groups. Theseembodiments are illustrated, respectively, in the copending application,by (a) a mixture of cellulose acetate and cellulose acetate hydrogenphthalate and (b) a cellulose acetate hydrogen phthalate polymer havinga much lower percentage of phthalyl groups than the first-mentionedcellulose acetate hydrogen phthalate.

It is also disclosed that the layer containing the polymeric acid maycontain a water-insoluble polymer, preferably a cellulose ester, whichacts to control or modulate the rate at which the alkali salt of thepolymer acid is formed.

In addition, as disclosed in the last-mentioned patent, an inert spacerlayer, for example, comprising polyvinyl alcohol or gelatin may beemployed to time control the pH reduction by the polymeric acid layer asa function of the rate at which alkali diffuses through the spacerlayer.

As disclosed in the previously cited patents, the liquid processingcomposition referred to for effecting multicolor diffusion transferprocesses comprises at least an aqueous solution of an alkalinematerial, for example, diethylamine, sodium hydroxide or sodiumcarbonate and the like, and preferably possessing a pH in excess of 12.Where this liquid processing composition is to be applied to thephotosensitive emulsion stratum by being spread thereon, preferably in arelatively thin and uniform layer intermediate that stratum and asuperposed image-receiving layer, it is disclosed to include aviscosity-increasing compound constituting a film-forming material ofthe type which, when the composition is spread and dried, forms arelatively firm and relatively stable film. The preferred film-formingmaterials disclosed comprise high molecular weight polymers such aspolymeric, watersoluble ethers which are inert to an alkaline solutionsuch as, for example, a hydroxyethyl cellulose or sodium carboxymethylcellulose. Additionally, film-forming materials or thickening agentswhose ability to increase viscosity is substantially unaffected if leftin solution for a long period of time are also disclosed to be capableof utilization. As stated, the film-forming material is preferablycontained in the processing composition in such suitable quantities asto impart to the composition a viscosity in excess of 100 cps. at atemperature of approximately 24 C. and preferably in the order of100,000 cps. to 200,000 cps. at that temperature.

For the production of the photoresponsive gelatino silver halideemulsions employed to provide the film unit, the silver halide crystalsmay be prepared by reacting a Water-soluble silver salt, such as silvernitrate, with at least one water-soluble halide, such as ammonium,potassium or sodium bromide, preferably together with a correspondingiodide, in an aqueous solution of a peptizing agent such as a colloidalgelatin solution; digesting the dispersion at an elevated temperature,to provide increased crystal growth; washing the resultant dispersion toremove undesirable reaction products and residual water-soluble salts bychilling the dispersion, noodling the set dispersion, and washing thenoodles with cold water, or, alternatively, employing any of the variousfloc systems, or procedures, adapted to effect removal of undesiredcomponents, for example, the procedures described in US. Pats. Nos.2,614,928; 2,614,929; 2,728,662; and the like; after-ripening thedispersion at an elevated temperature in combination with the additionof gelatin and various adjuncts, for example, chemical sensitizingagents of US. Pats. Nos. 1,574,944; 1,623,499; 2,410,689; 2,597,856;2,597,915; 2,487,850; 2,518,698; 2,521,926; and the like; all accordingto the traditional procedures of the art, as described in Neblette, C.3., Photography, Its Materials and Processes, 6th ed., 1962.

Optical sensitization of the emulsions silver halide crystals may beaccomplished by contact of the emulsion composition with an effectiveconcentration of the selected optical sensitizing dyes dissolved in anappropriate dispersing solvent such as methanol, ethanol, acetone,water, and the like; all according to the traditional procedures of theart, as described in Hammer, F. M., The Cyanine Dyes and RelatedCompounds.

Additional optional additives, such as coating aids, hardeners,viscosity-increasing agents, stabilizers, preservatives, and the like,for example, those set forth hereinafter, also may be incorporated inthe emulsion formulation, according to the conventional procedures knownin the photographic emulsion manufacturing art.

The photoresponsive material of the photographic emulsion will, aspreviously described, preferably comprise a crystal of silver, forexample, one or more of the silver halides such as silver chloride,silver iodide, silver bromide, or mixed silver halides such as silverchlorobromide or silver iodobromide, of varying halide ratios andvarying silver concentrations.

The emulsions may include the various adjuncts, or addenda, according tothe techniques disclosed in the art, such as speed-increasing compounds,stabilizers, hardening agents, coating aids, plasticizers, and the like.

As the binder for the respective emulsion strata, the aforementionedgelatin may be, in whole or in part, replaced with some other colloidalmaterial such as albumin; casein; or zein; or resins such as a cellulosederivative, as described in U.S. Pats. Nos. 2,322,085 and 2,327,- 808;polyacrylamides, as described in US. Pat. N0. 2,541,474.

While transfer of oxidized dye developer according to the previouslydesirable diffusion transfer process is substantially excluded, it hasbeen found that in instances at least some, albeit minimal amounts, ofoxidized dye developer does in fact transfer to the image-receivingelement. This transfer of oxidized dye developer results in less thanperfect color rendition, separation and/ or isolation, which in turnaffects the color fidelity of the transfer image and, hence, isundesired. The greater the transfer of oxidized dye, the poorer theacuity of the transfer image. The undesired transfer of oxidized dyedeveloper is believed to be due primarily to the fact that the mobilityof the oxidation product, i.e., the oxidized dye developer, may not besufficiently low in a selected processing composition to prevent atleast minimal transfer of dye and even such minimal transfer may affectto a degree the quality of the dye transfer image. In multilayerphotosensitive elements, the unwanted transfer of dye from exposed areasmay also be due, at least in part, to reduction of oxidized dyedeveloper by uuoxidized dye developer diffusion d'uring processing fromthe photosensitive element toward the image-receiving element. In fact,such reduc tion of oxidized dye in multilayer photosensitive elementsstatistically permits of greater transfer of undesired dye than thatobtained by transfer of dye developer in its oxidized form.

To obviate the problem of undesired transfer of oxidized dye developeralong with uuoxidized dye developer (or reduction of oxidized dyedeveloper and subsequent transfer thereof), it has heretofore beensuggested to employ certain additives which will react with the oxidizeddye developer to render it even less mobile and less diffusible, therebyprecluding transfer.

For example, in aforementioned US. Pat. No. 2,983,- 606, it is suggestedthat, when employing a dye developer having a free amino group as a partof its developing function, e.g., an aminophenol or diaminobenzenedeveloping function, a dye, or coupler capable of coupling with theoxidized developer to provide a less mobile reaction product, may alsobe employed.

In addition to the above-mentioned use of dyes and couplers which willcouple with the oxidation product of an amino-containing developingfunction of the foregoing description, US. Pat. No. 3,173,786 issued toMilton Green and Howard G. Rogers discloses the concept of employing anonium compound which not only will increase the transfer of the desireduuoxidized dye developer to increase the density of the dye image, butwill also inhibit transfer of oxidized dye developer to improve thehighlights. The latter concept is particularly useful since it may beemployed in conjunction with dye developers containing a hydroquinonyldeveloping function, which, as was heretofore noted, is the preferreddeveloper moiety.

It has now been quite unexpectedly discovered, however, that improvedpositive diffusion transfer monochromatic and multichromatic images maybe provided by a photographic diffusion transfer color process whichcomprises selectively exposing a photographic film unit which includes aphotosensitive element comprising a photosensitive silver halideemulsion having associated therewith a dye developer; contacting thephotosensitive silver halide emulsion with an aqueous alkalineprocessing composition having an alkali concentration at which the dyedeveloper is ditfusible to a contiguous image-receiving layer and anucleophilic reagent adapted to react with the oxidation product of thedye developer to provide a dye developer adduct substantiallynondiffusible in aqueous alkaline processing composition to a contiguousimagereceiving layer; effecting thereby development of the selectivelyexposed silver halide emulsion; forming thereby an imagewisedistribution of diifusible dye developer, as a function of thepoint-to-point degree of emulsion exposure; and transferring, bydiffusion, at least a portion of the image-wise distribution ofdiffusible dye developer to an image-receiving element which includes apolymeric layer dyeable by the dye developer to provide thereto a dyeimage in terms of the imagewise distribution.

Specifically, it has been unexpectedly discovered that theaforementioned diffusion transfer process employing an aqueous alkalineprocessing composition in which the dye developer is dilfusible may beimproved by being conducted in the presence of a nucleophilic reagentcapable of reacting with the oxidation product of the dye developer as afunction of and proportional to development, for example, a reactivenucleophilic reagent comprising a phenolic hydroxyl or amino groupadapted to react with oxidized dye developer, to provide a dye developeradduct which is less diifusible to a contiguous image-receiving layerthan oxidized dye developer and is thus substantially nondiffusible tosuch layer. By this mechanism there is thus provided an image wisedistribution of mobile, diffusible dye in terms of unexposed areas ofthe photosensitive emulsion for transfer by diffusion to a contiguousdye image-receptive element for production of an improved positive dyedeveloper transfer image.

Particularly suitable nucleophilic reagents comprise alpha and gammahydroxy and gamma amino pyridines which during diffusion transferprocessing provide a pyridine dye developer, nucleophilic adduct byaddition to oxidized dye developer, resultant from development ofexposed silver halide, proportional to and as a function of exposure,which adduct is less ditfusfble than oxidized dye developer at alkaliconcentrations at which reduced dye developer is diffusible to thecontiguous image-receiving element.

According to the present invention, undesired or unwanted transfer ofthe oxidation product of a dye developer, formed as a function of thedevelopment of an exposed photosensitive silver halide emulsion and/ orreduction of the oxidation product and subsequent transfer thereof, maybe obviated by utilizing in conjunction with such dye developer, anucleophilic reagent of the aforementioned type which is adapted toreact with dye developer oxidation product to provide a molecule whichis substantially less mobile, and preferably is effectively insolubleand nondilfusible, in the transfer processing composition employed. Asillustrative examples of particularly preferred reagents contemplatedfor employment in the practice of the present invention, mention may bemade of Various compounds particularly preferred for employment in thepractice of the present invention may be prepared by syntheticprocedures well known in the art, for example synthetic procedures ofthe types set forth in The Chemistry of Heterocyclic Compounds, vol. 14,Pyridine and Its Derivatives, Part 3, Chapter XII, Pyridinols andPyridines, Interscience Publishers, New York, N.Y., and the literaturearticles incorporated therein by reference and in particular, Bardhan,J. C., J. Chem. Soc., 1929, p. 2223 and Bassu, 1., Indian Chem. Soc. 7,815 (1930).

Among the plurality o synthetic procedures available for the productionof the preferred compounds, a particularly preferred procedure adoptedfor the expedious preparation of a multiplicity of such compounds inhigh yield may be represented synthetic process equation:

CNCH2CONH2 RCOCl+R COCHa ROOCHZCOR R @CEN R OH R- the CEN groups ofwhich may be readily removed, at the election of the operator, byalkaline hydrolysis and concurrent decarboxylation of the selectedcompound synthesized.

Although the reagents of the present invention are herein referred toand described employing the stated pyridine structural designation, itwill be recognized that the subject reagents may exist in any one ormore of the various isomeric (tautomeric) forms which are capable,theoretically at least, of changing into each other, and may be employedin any form active for the purpose of the invention, such as, forexample, the corresponding pyridine forms.

In a preferred embodiment of the present invention, the photosensitiveelement is employed which is specifi- CEN cally adapted to provide forthe production of a multicolor dye transfer image and comprises adimensionally stable support layer carrying at least two selectivelysensitized silver halide emulsion strata each having a dye developermaterial of predetermined color associated therewith is diffusible, inalkali at the selected processing concentration. The preferredphotoinsensitive image-receiving element comprises an alkaline solutionpermeable polymeric layer dyeable by the dye developer; a polymericspacer layer comprising a polymer possessing decreasing alkalinesolution permeability with increasing temperature; an alkaline solutionpermeable polymeric acid layer containing sufiicient acidifying groupsto effect reduction, subsequent to substantial multicolor transfer dyeimage formation, of the image-receiving elements initial alkaliprocessing concentration to a lower alkali concentration; and adimensionally stable transparent layer.

The silver halide emulsions comprising the multicolor photosensitivelaminate preferably possess predominant spectral sensitivity to separateregions of the spectrum and each has associated therewith a dye, whichis a silver halide developing agent and is diffusible in the reducedform at the alkali concentration employed for processing possessing,subsequent to processing, a spectral absorption range substantiallycomplementary to the predominant sensitivity range of its associatedemulsion.

In the preferred embodiment, each of the emulsion strate, and itsassociated dye, is separated from the remaining emulsion strata, andtheir associated dye, by separate alkaline solution permeable polymericinterlayers and the dyeable polymeric layer is separated from thepolymeric acid layer by an alkaline solution permeable polymeric spacerlayer having decreasing permeability to alkaline solution withincreasing temperature.

In such preferred embodiment of the invention, the silver halideemulsion comprises photosensitive silver halide dispersed in gelatin andis about 0.6 to 6 microns in thickness; the dye itself is dispersed inan aqueous alkaline solution polymeric binder, preferably gelatin, as aseparate layer about 1 to 7 microns in thickness; the alkaline solutionpermeable polymeric interlayers, preferably gelatin, are about 1 to 5microns in thickness; the alkaline solution permeable and dyeablepolymeric layer is transparent and about 0.25 to 0.4 mil. in thickness;the polymeric spacer layer intermediate the dyeable polymeric layer andthe polymeric acid layer is transparent and about 0.1 to 0.7 mil inthickness; the alkaline solution permeable polymeric acid layer istransparent and about 0.3 to 1.5 mils in thickness; and each of thedimensionally stable support layers are alkaline solution impermeableand about 2 to 6 mils in thickness. It will be specifically recognizedthat the relative dimensions recited above may be appropriatelymodified, in accordance with the desires of the operator, with respectto the specific product to be ultimately prepared.

In general, the optimum concentration of the specific pyridine to beemployed should be determined empirically for each specific photographiccolor transfer system employed. However, in general the preferredconcentration falls within the range of about 0.5 to 150 g. per 100 cc.of processing composition solvent, i.e., water, employed to effectprocessing of the film unit, depending upon the specific characteristicsof the individual dye developer or developers and pyridine or pyridinesselected. Although concentrations in excess of the range may beemployed, increasing the concentration beyond the stated limitsgenerally provides no additional beneficial results in most instances.Conversely, concentrations below that of the designated range, merelydecrease the effect of the additive below the effective level generallysought, but do not prevent operation of the invention. Where desired,however, substantial quantities of the additive may be employed withoutintroducing seriously deleterious photographic effects.

In the preferred embodiment of the present inventions film unit for theproduction of a multicolor transfer image, the respective silverhalide/dye developer units of the photosensitive element will be in theform of a tripack configuration which will ordinarily comprise a cyandye developer/red-sensitive emulsion unit contiguous the dimensionallystable support layer, the yellow dye developer/blue-sensitive emulsionunit most distant from the support layer and the magenta dyedeveloper/green-sensitive emulsion unit intermediate those units,recognizing that the relative order of such units may be varied inaccordance with the desires of the Operator.

The reagents of the present invention may be present initially in theprocessing composition, the photo-sensitive element and/or theimage-receiving element as a monomeric and/or polymeric reagent. Thereagent may be thus disposed, in the preferred multicolor film unit,associated with any or all of the emulsion layers constituting the filmunit, in a layer intermediate respective emulsion layers of the unitand/ or dye developer containing layers associated with the emulsions,and may be employed in conjunction with the onium compounds identifiedabove and/ or other such compounds as are known in the art forincreasing dye image fidelity.

Reference is now made to the drawing wherein there is illustrated apreferred film unit of the present invention.

As illustrated in the drawing, film unit 10 comprises a photosensitivelaminate 11 including, in order, dimensionally stable support layer 12,preferably a flexible sheet material; cyan dye developer layer 13;red-sensitive silver halide emulsion layer 14; interlayer 1S; magentadye developer layer 16; green-sensitive silver halide emulsion layer 17;interlayer 18; yellow dye developer layer 19; blue-sensitive silverhalide emulsion layer 20; auxiliary layer 21, which may contain anauxiliary silver halide developing agent; and an image-receiving element22 including image-receiving layer 23; spacer layer 24; neutralizinglayer 25; and dimensionally stable support layer 26, preferably aflexible sheet material. Each of emulsion layers 14, 17 and 20 mostpreferably contain a dispersion of the nucleophilic reagent adapted toreact with the oxidation product of its respective, associated dyedeveloper, as a function of and proportional to development of theemulsion layer, to provide a dye developer adduct less iffusible in aselected processing composition medium than oxidized dye developer.

As shown in the drawing, the multilayer exposed photosensitive element11 is shown in processing relationship with an image-receiving element22 and a layer 27 of processing solution distributed intermediateelements 11 and 22.

In the performance of a diffusion transfer multicolor process employingfilm unit 10, the unit is exposed to radiation, actinic tophotosensitive laminate 11.

Subsequent to exposure, film unit 10 may be processed by being passedthrough opposed suitably gapped rolls in order to apply compressivepressure to a frangible container in order and to effect rupture of thecontainer and distribution of alkaline processing composition 27, havingan alkali concentration at which the cyan, magenta and yellow dyedeveopers are dilfusible, intermediate dyeable polymeric layer 23 andauxiliary layer 21.

Alkaline processing solution 27 permeates emulsion layers 14, 17 and 20to initiate development of the latent images contained in the respectiveemulsions. The cyan, magenta and yellow dye developers, of layers 14, 17and 20, are mobilized, as a function of the development of theirrespective associated silver halide emulsions, preferably substantiallyas a result of their conversion from the diffusible reduced form totheir relatively nondifiusible adduct form, thereby providing imagewisedistribution of mobile, soluble and ditfusible cyan, magenta and yellowdye developer, as a function of the point-to-point degree of theirassociated emulsions exposure. At least part of the imagewisedistributions of mobile cyan, magenta and 1 ll yellow dye developertransfers, by diffusion, to aqueous alkaline solution permeablepolymeric layer 23 to provide a multicolor dye transfer image to thatlayer. Subsequent to substantial transfer image formation, a suflicientportion of the ions comprising aqueous alkaline solution 27 transfers,by diffusion, through permeable polymeric layer 23, permeable spacerlayer 24 and to permeable polymeric acid layer 25 whereby alkalinesolution 27 decreases in alkali concentration, as a function ofneutralization, to an alkali concentration providing enhanced stabilityto the multicolor dye transfer image.

Subsequent to substantial transfer image formation, print-receivingelement 22 may be manually dissociated from the remainder of the filmunit, for example, by stripping.

The present invention will be illustrated in greater detail inconjunction with the following specific examples which set outrepresentative photographic products and processes which, however, arealso intended to be illustrative and not of limiting efiect.

An image-receiving element of the type set forth in the drawing may beprepared by coating a cellulose nitrate subcoated opaque baryta paperwith the partial butyl ester of poly-ethylene/maleic anhydride copolymerprepared by refluxing, for 14 hours, 300 grams of DX-840-31 resin[tradename of Monsanto Chemical Co., St. Louis, Mo., for high viscositypoly-(ethylene/maleic anhydride) 140 grams of n-butyl alcohol and 1 cc.of 85% phosphoric acid to provide a polymeric acid layer approximately0.3 mil thick. The external surface of the acid layer may be coated witha 4% solution of polyvinyl alcohol in watermethanol-isopropanol toprovide a polymeric spacer layer approximately 0.15 mil thick. Theexternal surface of the spacer layer may then be coated with a 2:1mixture, by weight, of polyvinyl alcohol and poly-4-vinyl pyridine, at acoverage of approximately 600 mgs./ft.. to provide a polymericimage-receiving layer approximately 0.40 mil thick.

A multicolor, multilayer photosensitive element of the type set forth inthe drawing may be prepared in a manner similar to that disclosed in theaforementioned US. Pat. No. 3,345,163 and detailed hereinbefore. Ingeneral, the photosensitive elements may comprise an opaque supportcarrying a red-sensitive silver halide emulsion stratum, agreen-sensitive silver halide emulsion stratum and a bluesensitivesilver halide emulsion stratum, each containing a nucleophilic adjunct.In turn, the emulsions may have dispersed behind them inwater-immiscible organic solvents and contained in separate gelatinpolymeric layers, respectively, a cyan dye developer, a magenta dyedeveloper and a yellow dye developer. A gelatin interlayer may bepositioned between the yellow dye developer layer and thegreen-sensitive emulsion stratum, and also between the magenta dyedeveloper layer and the red-sensitive emulsion stratum. The particularnucleophilic reagent selected may comprise The particular dye developersemployed in the photosensitive elements may comprise1,4-bis-(a-methyl-{i-hydroquinonylethylamino -5,8-dihydroxyanthraquinone(a cyan dye developer); 2- p- [2,5 -dihydroxyphenethyl]-phenylazo)-4-isopropoxy-l-naphthol (a magenta dye developer); and1-phenyl-3-n-hexylcarbamyl 4(p-[hydroquinonylethyl]-phenylaZo--pyrazolone (a yellow dye developer).The last-mentioned yellow and magenta dye developers are disclosed inUS. Pat. No. 3,134,764 and the cyan dye developer is disclosed in U.S.Pat. No. 3,135,606.

12 The photosensitive element may then be exposed in a Polaroid LandCamera and processed by spreading an aqueous liquid processingcomposition comprising:

Watercc.

Hydroxyethyl cellulose (high viscosity) [commercially available fromHercules Powder Co., Wilmington, Del., under the trade name Natrosol250]3.8 g.

Potassium hydroxide1l.2 g.

Benzotriazole3.5 g.

between image-receiving element and the exposed multicolor element insuperposed relationship. After an imbibition period of about 60 seconds,the image-receiving element may be separated from the remainder of thefilm unit to reveal the requisite positive dye image formation.

Examination of resultant dye transfer prints will reveal image formationto be substantially completed and to exhibit the required color balance,hues, saturation and isolation, within the stated period.

For the explicit purpose of providing definitive comparative dataevaluating the unexpected and advantageous results obtained by means ofthe practice of the present invention, as compared with processesdisclosed in the prior art, two separate photosensitive elements wereprepared as detailed below.

The first photosensitive element was prepared by coating a gelatinsubcoat carrying opaque cellulose triacetate film base, in succession,with a layer comprising l-phenyl- 3-n-hexyl-carbamyl 4(p-[hydroquinonylethyl] -phenylaZo)-5-pyrazolone (a yellow dyedeveloper) in gelatin at a coverage of 54 mgs./ft. dye and 68 mgs./ft.gelatin; a layer comprising a greenand blue-sensitive gelatino silverhalide emulsion containing an ortho-hydroxy pyridine adjunct of thespecific formula CEN 1'1 HggCn \N OH and coated at a coverage of 193mgs./ft. silver, 183 mgs./ft. gelatin and 147 mgs./ft. pyridine; and agelatin layer coated at a coverage of 30 mgs./ft.

A second, optimized control photosensitive element was prepared as aboveby coating the gelatin subcoated opaque cellulose triacetate film basewith a layer comprising 54 mgs./ft. of the yellow dye developeridentified above; a greenand blue-sensitive gelatino silver halideemulsion comprising 176 mgs./ft. silver and 172 mgs./ft. gelatin; and agelatin layer coated at a coverage of 30 mgs./ft.

Each of the photosensitive elements were then selectively exposed toincident blue light and processed by spreading of the aqueous liquidprocessing composition set forth above between the thus exposedphotosensitive element and an image-receiving element of the structuredetailed above in superposed relationship. After a period of about 60seconds the respective image-receiving elements were separated from theremainder of the film units.

The test procedure was then repeated employing a processing compositionwhich additionally contained 1.9 grams of the quaternary salt compoundbenzylpyridini-um bromide and again repeated employing a processingcomposition which additionally contained 2.0 grams of the activequaternary salt compound benzyl-u-picolinium bromide.

The dye transfer images thus obtained detail the quantum of undesireddye transfer from areas of the photosensitive element corresponding tophotoexposed areas of the emulsion layer with which the dye wasassociated.

The number of density units and the percent improvement based upon thedifference of dye density units between the structure of the presentinvention, the control structure and the active and inactive quaternarycompound containing structures of the prior art is detailed hereinafterin the following table wherein the D f represents yellow dye density,respectively, of the transfer image, in areas of the image-receivingelement directly corresponding to areas of the photosensitive elementexposed to blue light.

3,039,869, issued June 19, 1962. As examples of suitable combinations ofauxiliary developing agents, mention may be made ofl-phenyl-3-pyrazolidone in combination with p-benzylaminophenol and1-phenyl-3-pyrazolidone in com- TABLE Density Density Densityimproveimproveimprovement vs. ment vs. ment vs. control inactive active(decrease quaternary quaternary Percent Percent Percent in dye systemsystem improveimproveimprovedensity (decrease (decrease ment vs. mentvs. ment vs. units) in dye in dye control inactive active densitydensity quaternary quaternary Dmin, units) units) system system Test 0.25 0.36 0. 35 0. 51 59 58 67 Control Inactive quaternary system Test andinactive quaternary system. Active quaternary system Test and activequaternary system 1 Equal to test results within degree of experimentalerror.

2 Competition with active quaternary compound for oxidized dye destroyedtest compound efiect. From the foregoing tabular date, it will bedirectly obbination with 2,5-bis-ethylenimino-hydroquinone. Such servedthat the compounds of the present invention materially reduce transferof oxidized yellow dye developer when directly compared with a controland prior art inactive and active onium systems; thus directlyincreasing the information fidelity of the photographic diffusiontransfer system employing such.

Although in each of the above examples a single reagent of the presentinvention was employed, it will be apparent that the simultaneous andrequential employment of two or more of such compounds is intended to bewithin the scope of this invention and that, as previously noted, one ormore of such agents may optionally be initially disposed in thephotosensitive element, the image-receiving element and/or theprocessing composition at the election of the operator. In addition, thecompounds of the present invention, unlike the onium compounds of theprior art, fail to exhibit the problems of density active, wheninitially disposed in the photosensitive element, as is inherent in theemployment of active onium compounds of the prior art.

The alkali concentration of the alkaline processing solution initiallyemployed must be a concentration at which the dye developers selectedare diffusible in their reduced form. Although it has been found thatthe specific alkali concentration to be employed may be readilydetermined emperically for any dye developer or group or dye developers,most particularly desirable dye developers are diffusible in alkaliconcentrations providing a pH above 9 and the system can be readilybalanced accordingly for such dye developers. In addition, although aspreviously noted, the processing composition, in the preferredembodiment, will include the stated film-forming viscosityincreasingagent, or agents, to facilitate spreading of the composition and toprovide maintenance of the spread composition as a structurally stablelayer of the laminate, subsequent to distribution, it is not necessarythat such agent be employed as a component of the composition. In thelatter instance, however, it will be preferred that the concentration ofsolvent, that is, water, etc., comprising the composition be the minimumamount necessary to conduct the desired transfer process, in order notto adversely affect the structural integrity of the laminate and thatthe layers forming the laminate can readily accommodate and dissipatethe solvent throughout during processing and drying without effectingundesirable dimensional changes in the layers forming the laminate.

It will be noted that the liquid processing composition employed aspreviously mentioned may contain an auxiliary or accelerating developingagent, such as p-methylaminophenol, 2,4-diaminophenol,p-benzylaminophenol, hydroquinone, toluhydroquinone, phenylhydroquinone,4- methylphenylhydroquinone, etc. It is also contemplated to employ aplurality of auxiliary or accelerating developing agents such as a3-pyrazolidone developing agent and a benzenoid developing agent, asdisclosed in US. Pat. No.

auxiliary developing agents may be employed in the liquid processingcomposition or they may be initially incorporated, at least in part, inany one or more of the silver halide emulsion strata, the stratacontaining the dye developers, the interlayers, the overcoat layed, theimage-receiving layer, or in any other auxiliary layer, or layers, ofthe film unit. It may be noted that at least a portion of the dyedeveloper oxidized during development may be oxidized and immobilized asa result of a reaction, e.g., an energy-transfer reaction, with theoxidation product of an oxidized auxiliary developing agent, the latterdeveloping agent being oxidized by the development of exposed silverhalide. Such a reaction of oxidized developing agent with unoxidized dyedeveloper would regenerate the auxiliary developing agent for furtherreaction with the exposed silver halide.

It will be apparent that the relative proportions of the agents of thediffusion transfer processing composition may be altered to suit therequirements of the operator. Thus, it is within the scope of thisinvention to modify the herein described developing compositions by thesubstitution of preservatives, alkalies, etc., other than thosespecifically mentioned, provided that the pH of the composition isinitially at the first pH required. When desirable, it is alsocontemplated to include, in the developing composition, components suchas restrainers, accelerators, etc. Similarly, the concentration ofvarious components may be varied over a wide range and when desirableadaptable components may be disposed in the photosensitive element,prior to exposure, in a separate permeable layer of the photosensitiveelement and/ or in the photo sensitive emulsion.

The dimensionally stable layers referred to may comprise any of varioustypes of conventional opaque and transparent rigid or flexiblematerials, for example, glass, paper, metal, and polymeric films of bothsynthetic types and those derived from naturally occuring products.Suitable materials include alkaline solution impermeable materials suchas polymethacrylic acid, methyl and ethyl esters; vinyl chloridepolymers; polyvinyl aeetal; polyamides such as nylon; polyesters such aspolymeric films derived from ethylene glycol terephthalic acid; andcellulose derivatives such as cellulose acetate, triacetate, nitrate,propionate, butyrate, acetate-propionate, or acetate-butyrate. It willbe recognized that one or more of the designated layers may not berequired where the remaining layers of the laminate are such as toprovide the functions of these layers in the absence of same, forexample, where the remaining layers of the laminate provide therequisite dimensional stability and radiation filtering properties.

In all examples of this specification, percentages of components aregiven by weight unless Otherwise indicated.

The present invention also includes the employment of a black dyedeveloper and the use of a mixture of dye developers adapted to providea black and white transfer image, for example, the employment of dyedevelopers of the three subtractive colors in an appropriate mixture inwhich the quantities of the dye developers are proportioned such thatthe colors combine to provide black.

Where in the specification, the expression positive image has been used,this expression should not be interpreted in a restrictive sense sinceit is used primarily for purposes of illustration in that it defines theimage produced on the image-carrying layer as being substantiallyreversed as to its conformation with respect to the silver image formedin the photosensitive emulsion layers.

In addition to the described essential layers, it will be recognizedthat the film unit may also contain one or more subcoats or layers,which, in turn, may contain one or more additives such as plasticizers,intermediate essential layers for the purpose, for example, of improvingadhesion, and that any one or more of the described layers may comprisea composite of two or more strata of the same, or different, componentsand which may be contiguous, or separated from, each other, for example,two or more neutralizing layers or the like, one of which may bedisposed intermediate the cyan dye image-forming component retaininglayer and the dimensionally stable support layer.

Since certain changes may be made in the above product and processwithout departing from the scope of the invention herein involved, it isintended that all matter contained in the above description or shown inthe ac companying drawing shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:

1. A photographic film unit which comprises a photosensitive elementcontaining photosensitive silver halide having associated therewith adye which is a silver halide developing agent and a compound selectedfrom the group consisting of alpha and gamma hydroxy and gamma aminosubstituted pyridines adapted to react with the oxidation product ofsaid dye to provide a dye-pyridine adduct less diffusible in aqueousalkaline solution than said dye.

2. A photographic film unit as defined in claim 1 wherein said dyeincludes a phenyl group containing at least two groups selected from thegroup consisting of hydroxy and amino groups, at least one of saidgroups substituted in one of ortho and para positions with respect toone other of said groups.

3. A photographic film unit as defined in claim 2 wherein said dyecontains at least one para dihydroxyphenol group.

4. A photographic film unit as defined in claim 3 wherein said compoundis 5. A photographic film unit as defined in claim 1 including animage-receiving element containing a polymeric layer dyeable by said dyeafiixed at least one edge of said phtotosensitive element and adapted tobe superposed on photosensitive element.

6. A photographic film unit as defined in claim 5 including a rupturablecontainer adapted to retain a fluid processing composition afiixed oneedge of one of said photosensitive and said image-receiving elements andto distribute its fluid contents intermediate said elements insuperposed relationship.

7. A photographic film unit as defined in claim 6 wherein said compoundis initially disposed in said fluid processing composition.

8. A photographic film unit as defined in claim 5 wherein saidimage-receiving element comprises a support carrying said dyeablepolymeric layer and retaining intermediate said support and said dyeablelayer a permeable polymeric acid layer.

9. A photographic film unit as defined in claim 1 wherein saidphotosensitive element comprises at least two selectively sensitizedsilver halide emulsion layers each having a dye, which dye is a silverhalide developing agent of predetermined color associated therewith.

10. A photographic film unit as defined in claim 9 wherein each of saidselectively sensitized silver halide emulsion layers possessespredominant spectral sensitivity to separate regions of the visiblespectrum and the dye associated with each of said silved halide emulsionlayers possesses subsequent to processing a spectral absorption rangesubstantially complementary to the predominant sensitivity range of itsassociated emulsion layer.

11. A photographic film unit as defined in claim 10 wherein saidphotosensitive element contains, as essential layers, a red-sensitivesilver halide emulsion layer, having cyan dye associated therewith, agreen-sensitive silver halide emulsion layer having magneta dyeassociated therewith, and a blue-sensitive silver halide emulsion layerhaving yellow dye associated therewith, each of said cyan, magenta andyellow dyes being silver halide developing agents.

12. A process of forming transfer images in color which comprises, incombination, the steps of:

(a) exposing a photographic film unit which includes,

in combination, a photosensitive element containing a photosensitivesilver halide emulsion having associated therewith a dye, which dye is asilver halide developing agent;

(b) contacting said photosensitive silver halide emulsion with anaqueous alkaline processing composition having an alkali concentrationat which said dye is diflusible and a compound selected from a groupconsisting of an alpha and gamma hydroxy and gamma amino pyridineadapted to react with the oxidation product of said dye to provide adye-pyridine adduct substantially nondiffusible to a superposedimage-receiving element which includes a polymeric layer dyeable by saiddye;

(c) effecting thereby development of said silver halide emulsion andoxidation of said dye as a function of the point-to-point degree ofemulsion exposure;

((1) forming thereby an imagewise distribution of diffusible dye; and

(e) transferring, by diifusion, at least a portion of said imagewisedistribution of diffusible dye to said image-receiving element toprovide thereto a dye image in terms of said imagewise distribution.

13. A process as defined in claim 12 wherein said photosensitive elementcomprises in contiguous relationship at least two selectively sensitizedsilver halide emulsion layers each having a dye, which dye is a silverhalide developing agent, of predetermined color associated therewith,each of said dyes nondiffusible in said processing composition at saidalkali concentration.

14. A process as defined in claim 13 wherein each of said selectivelysensitized silver halide emulsion layers possess predominant spectralsensitivity to separate regions of the visible spectrum and the dyeassociated with each of said emulsion layers possesses subsequent toprocessing a spectral absorption range substantially complementary tothe predominant sensitivity range of its associated emulsion layer.

15. A process as defined in claim 14 wherein each of said silver halideemulsion layers and its associated dye is separated from the nextadjacent layer and its associated dye by an alkaline solution permeablepolymeric interlayer.

16. A process as defined in claim 15 wherein said photosensitive elementcontains, as essential layers, in sequence, a support layer; an alkalinesolution permeable polymeric layer containing cyan dye; a red-sensitivesilver halide emulsion layer; an alkaline solution permeable polymericlayer containing a magenta dye; a greensensitive silver halide emulsionlayer; an alkaline solution permeable polymeric layer containing ayellow dye; a blue-sensitive silver halide emulsion layer, each of saidcyan, magenta and yellow dyes being a silver halide developing agent andwherein said image-receiving element contains, as essential layers, insequence, an alkaline solution permeable polymeric layer dyeable by saiddyes; an alkaline solution permeable polymeric acid layer; and a supportlayer.

17. A photographic process as defined in claim 12 wherein said dyeincludes a phenyl group containing at least two groups selected from thegroup consisting of 15 18 19. A process as defined in claim 18 whereinsaid compound is References Cited UNITED STATES PATENTS 3,502,468 3/1970Rogers 96-29 J. TRAVIS BROWN, Primary Examiner A. T. SURO PICO,Assistant Examiner U.S. Cl. X.R.

